It really depends on the year the home was built in. If it's a pre HUD home, built before June 15, 1976, she may have a difficult time with 20% DP. Additionally, there are a lot of health concerns about pre HUD homes that she needs to know about.
Additionally, if it's a lease/rent park she needs to investigate the rental/least terms and make sure she's not going to get jacked on her rent. A lot of folks get build alive in MH parks where the landord keeps jacking up the rent. It can actually drive a person right out of a park.